1. Technical Field
The present invention relates to a liquid crystal device having a reflective or transflective display element and an electronic apparatus using the same, and more specifically, to a liquid crystal device capable of displaying a bright and high-contrast image and to an electronic apparatus using the same.
2. Background Art
In general, conventional liquid crystal devices have a structure in which a liquid crystal layer composed of liquid crystal molecules is interposed between a first substrate and a second substrate opposite to each other, and two polarizing plates are arranged in a spaced relation so as to interpose the liquid crystal layer therebetween. A liquid crystal device has been suggested in which a light scattering layer is arranged to improve the utilization efficiency of light or to widen a viewing angle of the screen on which images are displayed.
For example, as shown in FIG. 6, a reflective liquid crystal device comprises a liquid crystal panel 115 having a reflecting layer 111 and a liquid crystal layer 113, a retardation plate 117 arranged on the surface of the liquid crystal panel 115, an isotropic forward scattering plate 119 arranged on the surface of the retardation plate 117, and a polarizing plate 121 arranged on the surface of the forward scattering plate 119. In such a reflective liquid crystal device, external light incident through the polarizing plate 121 is scattered while passing through the forward scattering plate 119, and the scattered light is incident on the liquid crystal layer 115 through the retardation plate 117. Then, the light incident on the liquid crystal panel 115 passes through the liquid crystal layer 113 and is then reflected from the reflecting layer 111. Subsequently, the reflected light passes through the liquid crystal layer 113 and the retardation plate 117 again. Then, the reflected light is scattered in the forward scattering plate 119 and is then incident on the reflecting plate 121. When the liquid crystal layer 113 is a normally white type and no voltage is applied thereto, light can pass through the polarizing plate 121, resulting in a white display. On the other hand, when a voltage is applied, light is shielded by the polarizing plate 121 from the relationship between the oscillating direction of the light and the transmission axis of the polarizing plate 121, resulting in a black display.
A liquid crystal device has been suggested in which a scattering polarizing plate having both a scattering function and a polarizing function is used instead of using the forward scattering plate having only the scattering function.
That is, in the liquid crystal device in which a backlight, a polarizing plate, a liquid crystal cell, and another polarizing plate are deposited in this order, the polarizing plate on the backlight is generally formed by depositing a light-scattering type polarizing element and a light-absorbing type polarizing element in this order from the backlight, wherein the light-scattering type polarizing element has a polarization selecting layer for selectively passing a predetermined light component of linearly polarized light components and for selectively reflecting and scattering the other light components, and the light-absorbing type polarizing element has a polarization selecting layer for selectively passing a predetermined light component of the linearly polarized light components and for selectively absorbing the other light components. In the above-mentioned liquid crystal device, the polarized light transmitting axis of the light-scattering type polarizing element is substantially parallel to the polarized light transmitting axis of the light-absorbing type polarizing element, and the polarized light selecting layer of the light-absorbing type polarizing element is formed on the polarized light selecting layer of the light-scattering type polarizing element by a coating method.
However, in the liquid crystal device shown in FIG. 6, since all light components are scattered by an isotropic forward scattering plate, light scattering occurs even in a black display mode. As a result, some light components pass through the polarizing plate, and thus light cannot be completely shielded, thereby generating an image blur and the deterioration of contrast.
In the meantime, the main object of the illustrated conventional example is to improve the utilization efficiency of light using a thin liquid crystal device equipped with a scattering polarizing plate, but high contrast is not obtained by the liquid crystal device.
As a result of the inventors' assiduous examination, the inventors find the fact that a bright and high-contrast image display can be achieved in a liquid crystal device equipped with a forward scattering type polarizing plate having a transmission axis and a diffusion axis by appropriately arranging the forward scattering type polarizing plate and a polarizing plate.